Hellam Township is reputed to feature seven remote gates, which when passed through in the right order, open an entrance to hell.

A recreation of the doomed ocean liner in the middle of the Smoky Mountains.

Wild lights and sound effects turn a walk through some caves into an eye-popping 1960s tourist attraction.

This defunct, fortress-like prison has been the setting for several movies.

The first full-scale tunnel built in America is short but scenic.

Remembering the Alamo with a full-scale replica of the 1836 city.

A house carved into a rock in the 1940s.

A small oasis not far from downtown Moab.

A pair of large white marble lions guard this stretch of the Mojave Desert, and it is utterly mysterious how they got there.

A volcanic tunnel illuminated by natural skylights offers a shaded respite from the desert sun.

One of the first intercontinental ballistic missile sites in the United States.

A devilishly named gorge that was a sign of salvation for many pioneers.

An impressive waterfall nestled in the cliffs of Idaho's Snake River Canyon.

These falls, sometimes called the "Niagara of the West," still put on a good show at the right time of year.

Operational for less than a year, this mill produced more than 11,000 tons of chrome concentrate in its short lifespan.

Home to the deepest rift anywhere on Earth.

A creek tumbles over a series of step-like rocks to create this scenic water feature.

This rustic old building is said to be the most photographed barn in America.

The residents at this Yellowstone wildlife park will certify your cooler as "bear-proof."

Creek water that starts here has a 50/50 chance of ending up in the Atlantic or the Pacific.

Native Americans built this circle of stones, which was used to predict astronomical events.

Yes, this monument is aware that it is about 20 miles away from the actual center of the United States.

The world's largest mountain carving could fit all of Mount Rushmore inside it many times over.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.